/* ============================================================
   PLAN — Components：Navbar / Theme Switch / Buttons / Footer
   ============================================================ */

/* ---------- Navbar ---------- */

.navbar {
  position: sticky;
  top: 0;
  z-index: 60;
  height: var(--nav-h);
  background: transparent;
  border-bottom: 1px solid transparent;
  transition: background-color 0.35s ease, border-color 0.35s ease;
}
.navbar.is-scrolled {
  background: var(--nav-bg);
  -webkit-backdrop-filter: blur(14px) saturate(1.5);
  backdrop-filter: blur(14px) saturate(1.5);
  border-bottom-color: var(--border);
}
.navbar-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  height: 100%;
}
.brand {
  font-size: 15px;
  font-weight: 700;
  letter-spacing: 0.16em;
  line-height: 1;
  white-space: nowrap;
}
.nav-right {
  display: flex;
  align-items: center;
  gap: clamp(12px, 2vw, 24px);
}
.nav-link {
  font-size: 14px;
  color: var(--text-2);
  white-space: nowrap;
  transition: color 0.2s ease;
}
.nav-link:hover {
  color: var(--text);
}
.nav-link-xu {
  font-weight: 600;
  color: var(--text);
}
.nav-link-xu:hover {
  color: var(--accent);
}

/* ---------- Theme Switch ---------- */

.theme-switch {
  display: flex;
  align-items: center;
  gap: 2px;
  padding: 3px;
  border: 1px solid var(--border);
  border-radius: 999px;
}
.theme-switch button {
  display: grid;
  place-items: center;
  width: 32px;
  height: 26px;
  border-radius: 999px;
  color: var(--text-3);
  transition: color 0.2s ease, background-color 0.2s ease, box-shadow 0.2s ease;
}
.theme-switch button:hover {
  color: var(--text);
}
.theme-switch button[aria-pressed="true"] {
  background: var(--surface);
  color: var(--text);
  box-shadow: 0 1px 4px rgba(0, 0, 0, 0.1);
}
.theme-switch svg {
  width: 14px;
  height: 14px;
}

/* ---------- Buttons ---------- */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  height: 48px;
  padding: 0 26px;
  border-radius: 12px;
  font-size: 15px;
  font-weight: 500;
  letter-spacing: 0.01em;
  white-space: nowrap;
  user-select: none;
  transition: transform 0.3s var(--ease), background-color 0.3s ease,
    border-color 0.3s ease, color 0.3s ease, box-shadow 0.3s ease;
}
.btn .arr {
  width: 15px;
  height: 15px;
  transition: transform 0.3s var(--ease);
}
.btn:hover .arr {
  transform: translateX(3px);
}
.btn:active {
  transform: translateY(1px);
}
.btn-primary {
  background: var(--btn-bg);
  color: var(--on-accent);
}
.btn-primary:hover {
  background: var(--btn-bg-hover);
  transform: translateY(-1px);
  box-shadow: var(--btn-shadow);
}
.btn-ghost {
  border: 1px solid var(--border-strong);
  color: var(--text);
  background: transparent;
}
.btn-ghost:hover {
  background: var(--bg-soft);
  border-color: var(--text-3);
  transform: translateY(-1px);
}

/* ---------- Footer ---------- */

.footer {
  border-top: 1px solid var(--border);
  padding: 52px 0 40px;
}
.footer-inner {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 28px 40px;
  flex-wrap: wrap;
}
.footer-logo {
  display: block;
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 0.16em;
}
.footer-series {
  display: block;
  margin-top: 8px;
  font-size: 13px;
  color: var(--text-3);
}
.footer-nav {
  display: flex;
  align-items: center;
  gap: 22px;
  font-size: 13.5px;
  color: var(--text-2);
}
.footer-nav a {
  transition: color 0.2s ease;
}
.footer-nav a:hover {
  color: var(--text);
}
.footer-bottom {
  margin-top: 44px;
  font-size: 12.5px;
  color: var(--text-3);
}

/* ---------- 小屏微调 ---------- */

@media (max-width: 380px) {
  .brand {
    font-size: 14px;
  }
  .nav-right {
    gap: 10px;
  }
  .theme-switch button {
    width: 28px;
  }
}

@media (max-width: 560px) {
  .footer-inner {
    flex-direction: column;
  }
}